[e2e] end of interest
David P. Reed
dpreed at reed.com
Sun May 11 07:52:10 PDT 2008
Snooping honors the Layeristi - granting them rhetorical power they
never deserved. It sounds like "cheating" or "illegal" operation. The
Internet was born without layers - it used architectural framing
differently (e.g., one arch principle illustrative: encapsulation is not
layering, and even survives as IP gets encapsulated in TCP port 8 VPNs,
much to the chagrin of the Layeristi purists who explain it as a "bug",
rather than looking at its roots in passing IP datagrams over SNA and
NCP virtual circuits).
I'd suggest that first-principles thinking is harder than Jon thinks.
It's not just a matter of choosing sides in a war, or acting as an arms
merchant to both sides. It's about thinking more squarely about the
real underlying issues that comprise communications . In fact, as some
of us have suggested, perhaps the idea that communications can be
considered as a "pure" architectural/linguistic frame independent of
storage and computation and sensing is the real issue we ought to be
addressing today, with pervasive comms/storage/computational elements
capable of all three.
John Day wrote:
> At 9:08 +0100 2008/05/11, Jon Crowcroft wrote:
>> nice example of 0nership by warring protocol layer factions
>>
>> mesh wifi people need to learn to do layer 3 snooping
>> same way telecom people did...
>
> The need to do snooping is an indication of the current model's
> inability or refusal to innovate. A failure to dig more deeply into
> the model. (Or a fear to challenge their religion.)
>
> (It turns out once there is a complete architecture, not one of these
> DOS look-a-likes, snooping isn't necessary.)
>
>>
>> there's a great e2e topic -
>> we have sort of gotten out of the
>> denial phase on middle boxes and
>> we're probably ok with multicast's niches now ...
>
> Middleboxes are alos an artifact of an incomplete architecture. In a
> full (shall we say, a wff) architecture, they aren't necessary.
>
>>
>> but should we raise the
>> art of _snooping_ to being a
>> first class component of any decent
>> postmodern internet architecture?
>
> No, snooping is an admission of failure. Calling it a component of a
> "decent" internet architecture is merely making excuses for our failures.
>
>>
>> knowing
>> multicast group members locations from lookin at IGMP traffic from
>> "below"
>> is one exxaple (think dslams too) but another would be
>> P2P aware Traffic Engineering, for example
>
> Recognizing that a multicast address is the name of a set deals with
> most of this. (Of course, this means that strictly speaking multicast
> addresses aren't really addresses but names.) A multicast or anycast
> address must always resolve at some point to a normal address. The
> idea of a multicast address as an ambiguous address is fundamentally
> broken.
>
>>
>> "layer violations" as taught in protocls #101 has traditionally
>> been restricted to upper layer tweaking layer-2 operating parameters
>> (think Application/TCP causing Dial up), rather than
>> vice versa - but the other way round stretches
>> programming API paradigms more athletically
>> so may be condusive to progress...
>
> If I understand what you are alluding to, this is addressed by not
> ignoring the existence of the enrollment phase in communication.
>
> What I have found is that in a wff architecture there are no need for
> layer violations. In other words, if you have layer violations, you
> are doing something wrong some place. Either in how you are trying to
> do what you want to do, or in what you think a layer is. In this case
> it seems to be a bit of both.
>
> Take care,
> John
>
>>
>> In missive <1210445625.6167.138.camel at jg-laptop>, Jim Gettys typed:
>>
>> >>On Sat, 2008-05-10 at 12:18 -0400, David P. Reed wrote:
>> >>
>> >>> There are huge aspects of that future that depend on getting the
>> >>> low-level abstractions right (in the sense that they match real
>> physical
>> >>> reality). And at the same time, constructing a stack of
>> abstractions
>> >>> that work to maximize the utility of radio.
>> >>>
>> >>
>> >>First hand reality in the OLPC project: use of multicast/broadcast
>> based
>> >>protocols when crossed with nascent wireless protocols (802.11s), can
>> >>cause spectacularly "interesting" (as in Chinese curse) interactions.
>> >>
>> >>First hand experience is showing that one had better understand what
>> >>happens at the lowest wireless layers while building application
>> >>middleware protocols and applications.... Some existing protocols
>> that
>> >>have worked well on wired networks, and sort of worked OK on
>> 802.11abc
>> >>networks, just doesn't work well (or scale well) on a mesh
>> designed to
>> >>try to hide what's going on under the covers.
>> >>
>> >>While overlays are going to play an important role in getting us
>> out of
>> >>the current morass (without transition strategies, we're toast;
>> that was
>> >>what got the Internet out of telecom circuit switching as the only
>> >>mechanism), I have to emphatically agree with Dave that we'd
>> better get
>> >>moving on more fundamental redesign and rethinking of networking....
>> >> - Jim
>> >>
>> >>--
>> >>Jim Gettys <jg at laptop.org>
>> >>One Laptop Per Child
>> >>
>>
>> cheers
>>
>> jon
>
>
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